Senior Thin-film Materials Engineer (inorganic)

Rivercell; Paris; Hybrid; EUR 100,000 - 130,000; Full time

Benefits offered by this job

Equity package

Career growth opportunities

Job summary

Rivercell seeks a Senior Thin-film Materials Engineer to own the inorganic material stack at the core of its platform. You will combine materials science, deposition-process engineering, device physics and reliability to develop photoconductor, dielectric layers, and their interfaces as an integrated system.

You will work with a cross-disciplinary team, including microfluidics, surface science, and AI, to enable strong optical switching and reproducible fabrication.

Qualifications

• PhD in materials science, applied physics, semiconductor engineering or related field.
• 5+ years of relevant experience developing semiconductor and/or dielectric thin films, including hands-on deposition and characterization.
• Fluent in English; French helpful but not required.

Responsibilities

• Develop and optimize a-Si:H and dielectric/multilayer stacks (SiNₓ, SiO₂, Al₂O₃) and assess interfaces.
• Translate chip-level requirements into specs for conductivity, ON/OFF ratio, spectral response and lifetime.
• Optimize photoconductor properties and deposition processes (PECVD, ALD, sputtering) for reliability and reproducibility.
• Engineer interfaces and multilayer architectures to balance voltage, optical performance and manufacturability.
• Plan and execute development campaigns with labs, cleanrooms, partners and vendors.
• Characterize electrical, optical, and structural properties and interpret results.

Skills

Materials science

Experimental design

Device physics

Team collaboration

Education

PhD in materials science / applied physics / semiconductor engineering

Tools

PECVD

ALD

Sputtering

PVD

Job description

We are looking for a Senior Thin-film Materials Engineer to develop and own the inorganic material stack at the heart of Rivercell's platform.

You will combine materials science, deposition-process engineering, device physics, and reliability to develop the photoconductor, dielectric layers, and their interfaces as one integrated system. Your objective will be to achieve strong optical switching, reliable high-field operation, and a reproducible fabrication process.

You will work hand-in-hand with our microfluidic chip lead, surface scientist, characterization engineer, and assembly team, as well as an interdisciplinary team spanning genetic engineering, AI and software, bio-laboratory automation, optics, electronics, and biology. You will be an integral part of an ambitious and exciting startup project from its inception.

• Develop and optimize a-Si:H and evaluate alternative photoconductive materials, together with dielectric layers and multilayers based on SiNₓ, SiO₂, Al₂O₃, and related materials

• Translate chip-level requirements into specifications for conductivity, ON/OFF ratio, spectral response, capacitance, leakage, breakdown strength, optical transmission, stress, uniformity, and lifetime

• Optimize photoconductor properties including dark and illuminated conductivity, response time, absorption, defect density, hydrogen incorporation, thickness, stress, and long-term stability

• Develop and tune PECVD, ALD, sputtering, or related deposition processes for composition, stoichiometry, density, hydrogen content, roughness, thickness uniformity, and process repeatability

• Engineer interfaces between the transparent electrode, photoconductor, dielectric stack, and upper surface while minimizing plasma damage, thermal degradation, interfacial defects, and delamination

• Design multilayer architectures that balance voltage distribution, photoconductor switching, capacitance, optical performance, dielectric strength, charge injection, charge trapping, and manufacturability

• Plan and execute structured development campaigns with internal laboratories, external cleanrooms, research partners, and equipment vendors

• Characterize and interpret electrical, optical, and structural measurements, including impedance, leakage, breakdown, FTIR, ellipsometry, profilometry, and spectroscopy

• Investigate failure modes such as excessive dark current, insufficient photoconductivity, non-uniform switching, dielectric leakage, breakdown, charge drift, hydrogen loss, stress, pinholes, and process-induced damage

• Define process windows, test structures, material specifications, acceptance criteria, and the roadmap for transfer to scalable fabrication equipment

• Opportunity to work on a cutting-edge project in the field of biotech

• Opportunity to join an ambitious team and impactful startup among the first employees

• Competitive salary and equity package

• Exciting opportunities for personal and professional growth within the team

You have a PhD in materials science, applied physics, semiconductor engineering, electrical engineering, microelectronics, or a related field.You have 5+ years of relevant experience developing semiconductor and/or dielectric thin films, including hands-on deposition, characterization, and process optimization.You understand how material properties, interfaces, process conditions, and electrical fields interact at device level.You combine scientific curiosity with an engineering mindset focused on reproducibility, specifications, reliability, and practical execution.You are autonomous, committed, enthusiastic, and comfortable working with a can-do, creative, and challenging mindset.You are rigorous in experiment design, documentation, data interpretation, and communication of uncertainty.You have excellent communication skills and are fluent in English; professional proficiency in French is helpful but not required.You have previous experience in one or more of the following areas:PECVD, ALD, sputtering, PVD, or related thin-film deposition processesAmorphous semiconductors, dielectric materials, defect states, carrier transport, charge injection, and charge trappingElectrical, optical, and structural characterization of multilayer thin-film devicesCleanroom process development, design of experiments, process transfer, or work with external fabrication partnersIntegration of multilayer stacks in microelectronic, photovoltaic, display, MEMS, sensor, or optoelectronic devices